On Error Vb6.0
resources Windows Server 2012 resources Programs MSDN subscriptions Overview Benefits Administrators Students Microsoft Imagine Microsoft Student Partners ISV Startups TechRewards Events Community Magazine Forums Blogs Channel 9 Documentation APIs and reference Dev centers Samples Retired content We’re sorry. The content you requested has been removed. You’ll be auto redirected in 1 second. Visual Basic Language Reference Statements F-P Statements F-P Statements On Error Statement On Error Statement On Error Statement For Each...Next Statement For...Next Statement Function Statement Get Statement GoTo Statement If...Then...Else Statement Implements Statement Imports Statement (.NET Namespace and Type) Imports Statement (XML Namespace) Inherits Statement Interface Statement Mid Statement Module Statement Namespace Statement On Error Statement Operator Statement Option
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company Business Learn more about hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 6.2 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up Why would you ever use “On Error Goto 0”? up vote 19 down vote favorite 5 Why would you ever use "On Error Goto 0" in a VB6 app? This statement turns the https://msdn.microsoft.com/en-us/library/5hsw66as.aspx error handler off and would mean that any error would crash the app. Why would this ever be desirable? vb6 error-handling share|improve this question asked Apr 2 '12 at 20:37 CJ7 4,99232114220 4 Well, it's certainly a way of implementing fail-fast –Greg Hewgill Apr 2 '12 at 20:39 I don't have VB6 installed, but presumably any Goto statement to a non-existant label would crash the app. –Sam Axe Apr 2 '12 at 20:40 This http://stackoverflow.com/questions/9983464/why-would-you-ever-use-on-error-goto-0 sounds like a comment from somebody who either throws in On Error Resume Next at the head of each procedure and then has mysterious woes that can't be diagnosed, or one who puts in On Error GoTo MyHandler and there just pops up a MsgBox with the same error anyway. –Bob77 Apr 2 '12 at 21:14 2 Not true at all. It is commonly paired with On Error Resume Next and a test of Err.Number to do inline structured error handling. –Bob77 Apr 3 '12 at 0:52 1 @CraigJ: Remember that the error handling is for that procedure (and children) only. "Turning it off" is NOT global, and allows errors to be handled by the parent. –Deanna Apr 3 '12 at 15:28 | show 9 more comments 4 Answers 4 active oldest votes up vote 35 down vote In VB6, you can specify that you want errors to be handled by particular code later in the routine: Sub Bar() On Error Goto MyHandler ... ...some code that throws an error... ... Exit Sub MyHandler: ...some error handler code (maybe pops up a dialog) End Sub It may be the case, however, that the code that throws the error is localized, and you don't want that same handler for all of the rest of the code in the routine. In that case, you'd use "On Error Goto 0" as follows: Sub Bar() ... On Error G
Database Guide User login Username: * Password: * Request new password Home › Tutorials Error Handling In Visual Basic Level: Despite your best efforts to cover all possible contingencies, run-time errors will occur in your applications. You can and should http://www.vb6.us/tutorials/error-handling do all you can to prevent them, but when they happen you have to http://www.cpearson.com/excel/errorhandling.htm handle them. Introduction Trapping Errors at Run-Time Building Error Handlers Raising Your Own Errors Summary Introduction The various functions, statements, properties and methods available in Visual Basic and the components used in Visual Basic expect to deal with certain types of data and behavior in your applications. For example, the CDate() function can convert a value to a Date on error variable. The function is remarkably flexible in the type of information it can accept, but it expects to receive data that it can use to derive a date. If you provide input that it can't convert, it raises error number 13 - "Type mismatch" - essentially saying "I can't handle this input data." In an application, this type of error may be a program logic error (you simply passed the wrong data) or it on error vb6.0 may be a data entry error on the part of the user (you asked for a date and the user typed a name). In the first case, you need to debug the program to fix the mistake. However, there is no way for you to anticipate the behavior of the end users of the application. If the user enters data you can't handle, you need to deal with the situation. Dealing with errors at run-time is a two step process: Trap the Error Before you can deal with an error, you need to know about it. You use VB's On Error statement to setup an error trap. Handle the Error Code in your error handler may correct an error, ignore it, inform the user of the problem, or deal with it in some other way. You can examine the properties of the Err object to determine the nature of the error. Once the error has been dealt with, you use the Resume statement to return control to the regular flow of the code in the application. In addition to dealing with run-time errors, you may at times want to generate them. This is often done in class modules built as components of ActiveX server DLLs or EXEs. It is considered good programming practice to separate the user interface fro
three flavors: compiler errors such as undeclared variables that prevent your code from compiling; user data entry error such as a user entering a negative value where only a positive number is acceptable; and run time errors, that occur when VBA cannot correctly execute a program statement. We will concern ourselves here only with run time errors. Typical run time errors include attempting to access a non-existent worksheet or workbook, or attempting to divide by zero. The example code in this article will use the division by zero error (Error 11) when we want to deliberately raise an error. Your application should make as many checks as possible during initialization to ensure that run time errors do not occur later. In Excel, this includes ensuring that required workbooks and worksheets are present and that required names are defined. The more checking you do before the real work of your application begins, the more stable your application will be. It is far better to detect potential error situations when your application starts up before data is change than to wait until later to encounter an error situation. If you have no error handling code and a run time error occurs, VBA will display its standard run time error dialog box. While this may be acceptable, even desirable, in a development environment, it is not acceptable to the end user in a production environment. The goal of well designed error handling code is to anticipate potential errors, and correct them at run time or to terminate code execution in a controlled, graceful method. Your goal should be to prevent unhandled errors from arising. A note on terminology: Throughout this article, the term procedure should be taken to mean a Sub, Function, or Property procedure, and the term exit statement should be taken to mean Exit